Pneumatic floor nailing machine



Jan. 22, 1963 R. A. CONRAD 3,0 4,069

PNEUMATIC FLOOR NAILING MACHINE Filed July 24, 1961 3 Sheets-Sheet l INVENTOR. RENE ARTHUR CONRAD ATTORNEY Jan. 22, 1963 R. A. CONRAD PNEUMATIC FLOOR NAILING MACHINE 3 Sheets-Sheet 2 Filed July 24, 1961 Will! IN VEN TOR.

RENE ARTHUR CONRAD BY leam Emlufi- A TTORNEY Jan. 22, 1963 R. A. CONRAD PNEUMATIC FLOOR NAILING MACHINE 3 Sheets-Sheet 3 Filed July 24, 1961 7 fl W E a 8 w 0 H m \H M Q/ My w M a 88 8 l /a 0 A M 7 8 5 Mm W 8 8 8 M M o 5 x J I I4 ,;/TIH I i T 6 n fig aw 3 G United States Patent Oilice 3,074,069 Patented Jan. 22, 1963 3,074,069 PNEUMATIC FLOQR NAHJWG MACHINE Rene Arthur Conrad, Richmond, (Ialif, assignoi' to Harvey Dale Devine, San Francisco, Calif. Filed July 24, 1961, Ser. No. 126,145 2 Claims. (Cl. 1-1) This invention relates to a pneumatic floor nailing machine.

The object of this invention is to provide a pneumatic floor nailing machine which is complete in itself and consists of a motor-air compressor unit, a nail hopper, a nail feeder for feeding nails into a nail driving unit and pneumatic means for operating the last mentioned unit.

Another object of this invention is to utilize a comparatively small, compact motor-air compressor unit for operating the nail driving unit.

Another object of this invention is to provide a new nail driving unit operable by pneumatic means which unit drives nails rapidly and successfully into a floor and at a small expenditure of compressed air.

Another object of this invention is to provide a new mechanism for feeding nails into the nail driving unit.

Other objects and advantages will appear as the specification proceeds and the novel features of the device will be particularly pointed out in the claims hereto annexed.

In this specification and the annexed drawing, the invention is illustrated in the form considered to be the best but it is understood, that the invention is not limited to such form; and it is also to be understood that in and by the claims following the description, it is desired to cover the invention in whatsoever form it may be embodied.

My invention is illustrated in the accompanying drawings forming a part of this specification in which:

FIG. 1 is a side elevation of the machine, some parts being shown in section.

FIG. 2 is a front view of the machine, some parts being shown in section.

FIG. 3 is a vertical cross-section of the nail driving unit.

FIG. 4 is an elevation of said nail driving unit, as seen in the direction of the arrow A of FIG. 3.

FIG. 5 is a partial, vertical cross-section of the nail driving unit, showing the parts thereof in a difierent position.

FIG. 6 is a horizontal section of said nail driving unit taken along the line 66 of FIG. 3.

FIG. 7 is a plan view of the bottom of the nail hopper; and

FIG. 8 is an electric wiring diagram of the machine.

In detail, the nail driving machine includes a motorcompressor unit 1 which consists of an electric motor 2 and a compressor 3, operatively connected thereto, which unit may be of any type capable of compressing sufiicient amount of air at a desired pressure.

The unit 1 is supported by a frame 5 consisting of two pairs of parallel standards 6 and 7 connected on the top by a platform 8.

The frame 5 in turn is carried by a front end of a lower air tank 1%) which is substantially rectangular in plan view and is comparatively shallow. The tank It) is supported by a pair of caster wheels 11 arranged symmetrically in relation to the central vertical longitudinal plane of the machine. Each caster wheel is enclosed in a compartment 12 opened at the bottom.

A nail hopper 15 is arranged between the standards 6 and 7 and above the front end of said lower air tank. The hopper 15 contains a bottom 16 with a slot 17 therein of the width slightly larger than the diameter of the nail head to enable the nails to fall through on an inclined nail feeder 18 arranged under said slot 17 in alignment therewith. A guard plate 20 is hingedly secured to the frame 6 over said slot 17 and has its end adjustably supported by a bolt 22 so as to permit nails to move freely in the vicinity of said slot and drop thereinto. The nail feeder 18 consists of two parallel metal bars 23 separated by a slot 24 which is sufficiently wide to pass the nail shank only.

Therefore, when a nail falls from the hopper 15 on said inclined nail feeder its shank passes through the slot and the nail slides down said nail feeder, being supported by its head. Vertical air tanks 25 and 26 are arranged on the front end of the lower tank 10 on each side of the nail hopper, which tanks have passages connecting the same with the lower tank 10.

An air motor 30, which may be of any suitable type, as the Super Speed Air Motor, type BNSSEM, manufactured and sold by The Bellows Company of Akron, Ohio, and described in their bulletin BM25R, is mounted on the platform 8 in front of and above the nail hopper 15.

The air motor 313 comprises a vertically arranged cylinder 31 with a piston 32 therein. The head 33 of said motor contains a sliding valve (not shown in the drawings), manipulated by a pair of solenoids which move said valve so as to apply air pressure on said piston and move the same rapidly down and up and at the same time permitting the compressed air to be rapidly exhausted into the atmosphere upon the completion of each stroke.

A pipe 35 supplies compressed air from the storage tanks to the head 33, from which the air passes to the sliding valve and directly into the cylinder to apply the pressure on the top of the piston 32 and move the same downwardly, at which time the air in the lower portion of the cylinder is exhausted through a transfer tube 37 to said valve and to the atmosphere. Thereupon the sliding valve changes its position, as shall be explained hereinafter in detail, and the compressed air is delivered through said transfer tube to the lower portion of the cylinder for raising the piston. The air from the upper portion of the cylinder is exhausted directly to the atmosphere through said valve. The air motor 30 works with extreme rapidity. But the impact of its downward stroke, however, is insufiicient to drive a nail of desired size into a hardwood floor to a standard depth.

In order to increase the striking power of the downward stroke of said air motor, the following described structure was added to said motor.

A shaft 49 extends downwardly from said piston 32 and passes through a guide 41 secured to the platform ti. The end of said shaft 40 is threaded as shown at 42, and carries a Weight 43 in form of a short cylinder screwed thereon. A nut 44 looks the weight 43 on said shaft 40. A guide rod 45 is threaded into said weight from the bottom and extends downwardly into a lower guide 45 carried by a support 47 secured to the standards 6.

The weight 43 augments considerably the striking force of the down stroke of said motor 30, which force, augmented as aforesaid, becomes sufficient to drive 'a nail of the proper size to the proper depth into the floor. The upward stroke of said air motor easily lifts said piston, and weight 43 to its initial position. There is no other load except the weight of the aforesaid movable parts associated with the air motor.

The machine also includes a nail driver 50 which is vertically arranged in front and in close proximity of the guide rod 45 and carried by said support 47.

The nail driver comprises a substantially cylindrical spindle 51 having a central bore 52 therein in which a nail driving rod 53 slides. The latter extendsupwardly beyond said spindle and terminates with a head 55. The.

latter normally located under and in spaced relation to the weight 43 and is adapted to be struck by the latter on its downard stroke. The rod 53 is of considerably smaller diameter than the bore 52 and carries a spring keeper 57 which aligns the upper portion of said rod with the central line of said bore and also serves as an abutment for the upper end of a coil spring 58 arranged around said rodv The bore 52 narrows considerably, substantially in the middle of the spindle, to form a bearing so in which the lower end of said rod 53 slides also, and to form a sharply defined shoulder 61 on which the lower end of the spring 58 rests. The keeper 57 and the bearing 6% keep the rod 53 in strict alignment with the bore 52 and the spring 53 yieldingly urges the rod 53 upwardly and keeps the keeper 57 in abutment with a disk 62 secured'to the top of said spindle, thus limiting the upward movement of said keeper.

The spindle Slis slightly conical toward its lower end and terminates with a hammer guide 64 which is screwed into, or otherwise secured to, said spindle.

The guide 64 is provided with a centrally located passage 65 which is just sufiicient to pass the nail head through it. The passage 65 is flared outwardly at its upper end, as shown at 66, for the purpose of guiding the nails thereinto.

The rod 53 terminates with a hammer 6% which begins at the lower end ofthe bearing 60, when the rod is in its uppermost position, and extends downwardly to close proximity of said hammer guide. The hammer 69 is of considerably smaller diameter than that of the rod 53 and is of slightly smaller diameter than that of the passage 65. A lower portion 76 of'the bore 52 from the bearing 60 to the hammer guide 54 is of sufficient size to accommodate said hammer 69 and a nail which slides downwardly between said hammer and the inner Wall of the bore 7% to and into the passage 65 of the hammer guide. 7

Nails are delivered from the hopper 15 to the spindle 51 by the nail feeder l8, the'lower end of which is secured to a feeder retainer 71. The latter represents a block in form of an inverter U, to the inner sides of which the bars 23 of said feeder are attached. The retainer 71 is secured to said spindle by screws 72.. Nails slide down on said feeder by gravity enhanced by the vibration of the machine and enter the retainer 71 and are stopped by a cross slide 73'arranged across their path at the end of the feeder and behind said retainer. The cross slide 73 is arranged to slide horizontally in a groove 74 in said spindle and has on its side facing the feeder a round vertical groove '75 normally registering with the feeder slot 24. The diameter of the latter groove is large enough to accommodate a nail shank when a nail slides from said feeder into said groove. The slide '73 is operated by a flat spring 76 securedto the outer end of said slide, which spring extends upwardly, and the upper end of which is attached to the spindle by a screw 77.

The spring 7:? is actuated by a cam 80 arranged in the upper end of the spindle. The cam Ell is swingable about a pin 81 and normally protrudes slightly into the bar 52. When the nail driving rod 53 moves down the spring keeper 57 pushes the cam 8i) outwardly, as shown in FIG. 5, and causes it to swing about the pin 81, whereupon a second pin 82 carried by the lower end of said cam pushes the spring '76 outwardly and away from the spindle, thus pulling the cross-slide 73 outwardly.

When the slide 73 is pulled outwardly, it moves the nail, which previously dropped in the groove 74, away from the slot 24. An outer portion of the end of the left feeder bar 23 is cut off, as shown in FIGURES 4, and 6 to form a notch 83/ The nail being moved away from the slot 24 by said slide 73, is pushed out of said groove 74 by a curve 85 in the spindle 51, provided above said cross slide, into said notch 83, and therefrom into a guide block 85 secured to the spindle 51 under the feeder retainer 71. The guide block 86 is formed with a passage 87 leading to an opening 88 in the spindle, which opening terminates in the bore 70.

A pair of handle bars 96 extend from the support 47, by which the machine is guided on a floor by the operator standing on his knees in front thereof. The operator presses two press-button switches 91 located on said handle bars, whereupon the electrically operated slide valve in the valve head of the air motor 39 shifts to let the compressed air to move the piston with the shaft and the weight 43 downwardly. The weight 43 on its way down strikes the head of the nail driving rod 53 and forces the rod downwardly. The hammer 69 drives the nail, which is in the machine, in the floor. At the same time the spring keeper 57 actuates the cam and the spring 76, thus moving the stop slide 73 outwardly and discharging another nail into the spindle 51, as aforesaid.

When the weight 43 is in its lowermost position it strikes a spring swtich 92 attached to the frame 7 and actuates the same, whereupon the sliding valve is shifted to permit the flow of compressed air to move the piston upwardly. Thereupon the hammer 69 is withdrawn from the passage 65 of the hammer guide 64 before the nail drops into the spindle, thus permitting the nail to drop into said passage.

The spindle 51 is located in the most forward position of the machine so as to permit nails to be driven close to walls and other obstacles.

Compressed air from the compressor 3 is directed to the air tank 2 which is connected by a tube 95 with an air filter and lubricating device 96 wherein the air is filtered and lubricated and its pressure is automatically regulated. Any device, such as Lubri Air control unit manufactured and sold by the Bellows Company of Al:- ron, Ohio and described in their Bulletin LA-20, may be used for this purpose. The device 96 is connected by v the pipe 35 to the head 33 of the air motor 30.

FIG. 8 shows a wiring diagram of the machine in which wires 1% and fill connect a transformer 162 with a source of electric current. A wire 163 connects said transformer with a pair of solenoids 134 and 105, shifting the sliding valve 1'66 (shown diagrammatically). The

solenoid W4 is connected by a Wire 197 to the pressbutton switches 91, operable by the operator, the latter being connected to a wire res leading back to said transformer. When both switches 91 are pressed, the solenoid that is activated and it shifts the sliding valve 106 to move the piston 32 downwardly.

The solenoid is connected by a wire 11%) to the return switch 92, which is in turn connected by wire 111 to the wire 1299. When the weight 43 closes the switch 92 on its down stroke, the solenoid 165 is activated and it moves the sliding Valve so as to move the piston 32 upwardly to its initial position.

1 claim:

1. Afloor nail driving machine comprising a frame, carrying an air compressor a means for operating said compressor an air tank connected to said compressor;

an air motor arranged in the front part of said frame,

including a cylinder, a reciprocating piston and a rod connected to sm'd piston and extending downwardly outside said cylinder;

a weight secured to said rod for increasing the power of the downward stroke of said piston;

a nail driver for driving nails into a floor secured to V the front portion of said frame, and including a spindle and a nail driving rod sliding therein, said rod being located under said weight to be struck thereby and driven downwardly on the downward stroke of said weight;

a nail hopper and a nail feeder carried by said frame for feeding nails from said hopper into the nail driver;

electric control means for starting the downward stroke of said piston, rod and weight and for automatic return of the same to their initial position.

2. A floor nail driving machine comprising a frame carrying an electric motor-air compressor unit for compressing air, an air tank connected thereto for storing air compressed by said unit, and an air motor operable by compressed air and connected to said tank;

said air motor including a reciprocating piston, and a rod connected thereto, extending downwardly outside said air motor;

a weight secured to said rod for increasing the power of the downward stroke of said piston;

a nail driver secured to said frame under said weight, said nail driver including a spindle and a nail driving rod sliding therein, said nail driving rod being so located as to be struck by said weight on its downward stroke, and be driven downwardly a distance 6 sufiicient to force a nail into the floor a required distance;

means for adjusting the length of the downward stroke of said weight;

a nail hopper and a nail feeder carried by said frame for feeding nails from said hopper into the nail driver;

electric control means for starting the downward stroke of said piston, rod and weight and for returning the same automatically to their initial position.

References Cited in the file of this patent UNITED STATES PATENTS 1,499,887 Snyder July 1, 1924 1,703,458 Rufi Feb. 26, 192.9 2,806,219 Cavanaugh Sept. 17, 1957 2,897,503 Schafroth Aug. 4, 1959 2,925,048 McWilliams Feb. 16, 1960 

1. A FLOOR NAIL DRIVING MACHINE COMPRISING A FRAME, CARRYING AN AIR COMPRESSOR A MEANS FOR OPERATING SAID COMPRESSOR AN AIR TANK CONNECTED TO SAID COMPRESSOR; AN AIR MOTOR ARRANGED IN THE FRONT PART OF SAID FRAME, INCLUDING A CYLINDER, A RECIPROCATING PISTON AND A ROD CONNECTED TO SAID PISTON AND EXTENDING DOWNWARDLY OUTSIDE SAID CYLINDER; A WEIGHT SECURED TO SAID ROD FOR INCREASING THE POWER OF THE DOWNWARD STROKE OF SAID PISTON; A NAIL DRIVER FOR DRIVING NAILS INTO A FLOOR SECURED TO THE FRONT PORTION OF SAID FRAME, AND INCLUDING A SPINDLE AND A NAIL DRIVING ROD SLIDING THEREIN, SAID ROD BEING LOCATED UNDER SAID WEIGHT TO BE STRUCK THEREBY AND DRIVEN DOWNWARDLY ON THE DOWNWARD STROKE OF SAID WEIGHT; A NAIL HOPPER AND A NAIL FEEDER CARRIED BY SAID FRAME FOR FEEDING NAILS FROM SAID HOPPER INTO THE NAIL DRIVER; ELECTRIC CONTROL MEANS FOR STARTING THE DOWNWARD STROKE OF SAID PISTON, ROD AND WEIGHT AND FOR AUTOMATIC RETURN OF THE SAME TO THEIR INITIAL POSITION. 